// Copyright 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef UI_VIEWS_CONTROLS_PREFIX_SELECTOR_H_
#define UI_VIEWS_CONTROLS_PREFIX_SELECTOR_H_

#include <stddef.h>
#include <stdint.h>

#include "base/macros.h"
#include "base/strings/string16.h"
#include "base/time/time.h"
#include "ui/base/ime/text_input_client.h"
#include "ui/views/views_export.h"

namespace views {

class PrefixDelegate;

// PrefixSelector is used to change the selection in a view as the user
// types characters.
class VIEWS_EXPORT PrefixSelector : public ui::TextInputClient {
public:
    explicit PrefixSelector(PrefixDelegate* delegate);
    ~PrefixSelector() override;

    // Invoked from the view when it loses focus.
    void OnViewBlur();

    // ui::TextInputClient:
    void SetCompositionText(const ui::CompositionText& composition) override;
    void ConfirmCompositionText() override;
    void ClearCompositionText() override;
    void InsertText(const base::string16& text) override;
    void InsertChar(const ui::KeyEvent& event) override;
    ui::TextInputType GetTextInputType() const override;
    ui::TextInputMode GetTextInputMode() const override;
    int GetTextInputFlags() const override;
    bool CanComposeInline() const override;
    gfx::Rect GetCaretBounds() const override;
    bool GetCompositionCharacterBounds(uint32_t index,
        gfx::Rect* rect) const override;
    bool HasCompositionText() const override;
    bool GetTextRange(gfx::Range* range) const override;
    bool GetCompositionTextRange(gfx::Range* range) const override;
    bool GetSelectionRange(gfx::Range* range) const override;
    bool SetSelectionRange(const gfx::Range& range) override;
    bool DeleteRange(const gfx::Range& range) override;
    bool GetTextFromRange(const gfx::Range& range,
        base::string16* text) const override;
    void OnInputMethodChanged() override;
    bool ChangeTextDirectionAndLayoutAlignment(
        base::i18n::TextDirection direction) override;
    void ExtendSelectionAndDelete(size_t before, size_t after) override;
    void EnsureCaretInRect(const gfx::Rect& rect) override;

    bool IsEditCommandEnabled(int command_id) override;
    void SetEditCommandForNextKeyEvent(int command_id) override;

private:
    // Invoked when text is typed. Tries to change the selection appropriately.
    void OnTextInput(const base::string16& text);

    // Returns true if the text of the node at |row| starts with |lower_text|.
    bool TextAtRowMatchesText(int row, const base::string16& lower_text);

    // Clears |current_text_| and resets |time_of_last_key_|.
    void ClearText();

    PrefixDelegate* prefix_delegate_;

    // Time OnTextInput() was last invoked.
    base::TimeTicks time_of_last_key_;

    base::string16 current_text_;

    DISALLOW_COPY_AND_ASSIGN(PrefixSelector);
};

} // namespace views

#endif // UI_VIEWS_CONTROLS_PREFIX_SELECTOR_H_
